Backlight unit and liquid crystal display including the same

ABSTRACT

A backlight unit and a liquid crystal display including the same are provided. The backlight includes a light guiding plate, a reflector, and at least one LED assembly including an LED light source, a substrate, and a support plate. A plurality of protrusions formed on a cover of the liquid crystal display are configured to mate to a plurality of concave portions formed on the light guiding plate, the reflector, and the LED assembly to mount the various components of the liquid crystal display onto the cover.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority under 35 U.S.C. § 119 More than onereissue application has been filed for the reissue of U.S. Pat. No.8,456,592. The reissue applications are application Ser. No. 14/468,241filed on Aug. 25, 2014 (the present application) and Ser. No. 14/481,423filed on Sep. 9, 2014, which is a continuation reissue of reissueapplication Ser. No. 14/468,241. The reissue Ser. No. 14/468,241 claimspriority under 35 U.S.C. § 119(e) or 120, and 37 CFR 1.78 to KoreanApplication No. 10-2009-0108953 filed on Nov. 12, 2009, ProvisionalApplication Nos. 61/260,540 filed Nov. 12, 2009, and 61/301,358 filedFeb. 4, 2010, respectively, whose entire disclosure(s) is/are herebyincorporated by reference.

BACKGROUND

1. Field

A backlight unit and a liquid crystal display including the same aredisclosed herein.

2. Background

Backlight units and liquid crystal displays including the same areknown. However, they suffer from various disadvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments will be described in detail with reference to thefollowing drawings in which like reference numerals refer to likeelements, wherein:

FIG. 1 is a perspective view illustrating a liquid crystal displayaccording to an embodiment;

FIG. 2 is a partial perspective view illustrating a bottom cover of aliquid crystal display according to an embodiment;

FIG. 3 is a cross-sectional view illustrating an LED assembly and abottom cover of a liquid crystal display according to an embodiment;

FIG. 4 is a cross-sectional view illustrating an LED assembly coupled toa bottom cover;

FIGS. 5 and 6 are perspective views illustrating an LED assembly coupledto a bottom cover;

FIG. 7 is a cross-sectional view illustrating an LED assembly coupled toa bottom cover;

FIG. 8 is a top plan view and a cross-sectional view illustrating areflector of the liquid crystal display according to an embodiment;

FIG. 9 is a cross-sectional view illustrating a reflector coupled to abottom cover;

FIG. 10 is a partial perspective view illustrating the reflector coupledto a bottom cover;

FIG. 11 is a top plan view and a cross-sectional view illustrating alight guiding plate of the liquid crystal display according to anembodiment;

FIGS. 12 to 13 are cross-sectional views illustrating a light guidingplate coupled to a bottom cover;

FIG. 14 is a partial perspective view illustrating a light guiding platecoupled to a bottom cover;

FIG. 15 is a top plan view illustrating an area I of FIG. 14;

FIG. 16 is a partial perspective view illustrating shapes of concaveportions on a light guiding plate and a reflector of the liquid crystaldisplay according to an embodiment;

FIGS. 17 to 23 are cross-sectional views and perspective viewsillustrating a backlight unit according to another embodiment;

FIGS. 24 to 26 illustrate an LED light source of a backlight unit;

FIGS. 27 and 28 are top plan views illustrating a backlight unitaccording to another embodiment;

FIG. 29 is a top plan view illustrating a backlight unit according toanother embodiment;

FIG. 30 is a cross-sectional view illustrating a backlight unit takenalong line J-J′ of FIG. 29;

FIG. 31 is a top plan view illustrating a front surface of a backlightunit according to an embodiment; and

FIGS. 32 to 34 are top plan views illustrating a front surface of abacklight unit according to other embodiments.

DETAILED DESCRIPTION

Referring to FIG. 1, a liquid crystal display 100 according to anembodiment includes a liquid crystal panel 110, a backlight unit 130, amain support 140, a bottom cover 150, a side cover 155, a top cover 160,a bracket 170, a front case 180, and a rear case 190. The liquid crystalpanel 110 may display an image and may include a first substrate 111 anda second substrate 112 attached to a liquid crystal layer interposedthere between. Although not shown in FIG. 1, a plurality of scan linesand data lines may intersect in a matrix shape in the first substrate111 called a TFT array substrate, thereby defining a plurality ofpixels. Each pixel may be turned on or off by a thin film transistor(TFT) provided on each pixel, including a pixel electrode connectedthereto and positioned at the thin film transistor.

The second substrate 112 may be a color filter substrate that includescolor filters of a red color R, a green color G, and a blue color Bcorresponding to each of a plurality of pixels. The second substrate 112may also include a black matrix for enclosing the color filters and forcovering a non-display element such as a scan line. A data line and athin film transistor may also be provided. Further, a transparent commonelectrode for covering the color filters and the black matrix may beprovided in the second substrate 112.

A printed circuit board (PCB) 116 may be connected to at least one sideof the liquid crystal panel 110 using, as an intermediary, a connectionmember 114 formed of, for example, a flexible PCB, a tape carrierpackage (TCP), or other appropriate connecting structures. Thus, in amodularization process, the PCB 116 may be closely disposed at a sidesurface of the main support 140 or a rear surface of the bottom cover150.

In the liquid crystal panel 110 of this embodiment, when a thin filmtransistor, selected on a scan line basis, is turned on by an on/offsignal on a scan line, a data voltage may be transferred to acorresponding pixel electrode through a data line. Thus, an orientationof liquid crystal molecules may be changed due to an electric fieldbetween the pixel electrode and a common electrode, thereby representinga transmittance difference.

In the liquid crystal display 100 according to this embodiment, thebacklight unit 130 may provide light from a rear surface of the liquidcrystal panel 110. The backlight unit 130 may include an LED assembly120, a white color or silver color reflector 128, a light guiding plate131 (light guide panel) positioned on the reflector 128, and a pluralityof optical sheets 139 positioned at an upper part of the light guidingplate 131. The LED assembly 120 may be positioned at one side of thelight guiding plate 131 and may comprise a plurality of LED lightsources 121, a substrate 122 in which the LED light sources 121 may bemounted to be separated by a predetermined gap, and a support 123 thatmay be mounted on the bottom cover 150.

In the light guiding plate 131, light applied by the LED light source121 may be spread onto a wide area of the light guiding plate 131 aslight is reflected several times as it advances through the lightguiding plate 131. Thus, the light guiding plate 131 may provide aprimary surface light source to the liquid crystal panel 110. A rearsurface of the light guiding plate 131 may comprise various shapes orpatterns in order to supply a uniform surface light source. Further, thelight guiding plate 131 may comprise at least one first concave portion135 in order to be coupled and supported to the bottom cover 150.

The reflector 128 may be positioned at a rear surface of the lightguiding plate 131 to improve luminance of light by reflecting lightpassing through a rear surface of the light guiding plate 131 toward theliquid crystal panel 110. The reflector 128 may comprise at least onesecond concave portion 135 that may be coupled to the bottom cover 150.

A plurality of optical sheets 139 may be positioned on the light guidingplate 131 may including a diffusion sheet, a protection sheet, and afocusing sheet in which a prism or a microlens may be formed. Therefore,the optical sheet 139 may diffuse or focus the surface light from thelight guiding plate 131, thereby more uniformly providing the light tothe liquid crystal panel 110.

The liquid crystal panel 110 and the backlight unit 130 may bemodularized through the top cover 160, the main support 140, the bottomcover 150, and the side cover 155. The top cover 160 may have aquadrangular frame shape that covers an upper surface and a side surfaceof the liquid crystal panel 110 and displays an image generated on theliquid crystal panel 110 through an opening on a front surface of thetop cover 160.

The bottom cover 150 may function as a base for a liquid crystal displayand may couple the liquid crystal panel 110 and the backlight unit 130on a plate having a quadrangular shape. The bottom cover 150 maycomprise at least one first protruding portion 151 that may couple tothe light guiding plate 131 and at least one second protruding portion152 that may couple to the LED assembly 120. Further, the side cover 155may be coupled to the bottom cover 150. The main support 140 may have aquadrangular frame shape that may enclose the edge of the backlight unit130, and may also be coupled to the top cover 160.

A power supply PCB 171, to supply external power to the liquid crystalpanel 110 and the backlight unit 130, and a signal conversion PCB 172,to convert an external data signal may be separately provided. The powersupply PCB 171 and the signal conversion PCB 172 may be provided in thebracket 170. The bracket 170 may be positioned at a lower part of thebottom cover 150 to which the backlight unit 130 is coupled. A liquidcrystal display 100 may include a front case 180 and a rear case 190that encloses the bracket 170 and the coupled top cover 160 and bottomcover 150.

FIG. 2 is a partial perspective view illustrating a bottom cover of aliquid crystal display according to an embodiment. Referring to FIG. 2,the bottom cover 150 may comprise at least one first protruding portion151 and at least one second protruding portion 152. The first protrudingportion 151 and the second protruding portion 152 of the bottom cover150 may protrude upward from a surface of the bottom cover 150. Thefirst protruding portion 151 may be a post that has a sufficient heightto couple an LED assembly, a reflector, and a light guide plate. Thesecond protruding portion 152 may be a peg that has a lower heightrelative to the first protruding portion 151, and may be coupled to theLED assembly and positioned below the reflector 120.

The first protruding portion 151 and the second protruding portion 152may have a pillar shape. A lateral cross-section of the protrudingportions 151 and 152 may be a polygon, for example, a circle, atriangle, a quadrangle, or any other appropriate shape that may couplethe LED assembly, the reflector, and the light guiding plate.

The first protruding portion 151 may be positioned at a central part ofone side surface of the bottom cover 150. When the LED assembly ismounted in a front surface of the bottom cover 150, the first protrudingportion 151 may be positioned a predescribed distance from the sidesurface of the bottom cover 150 such that it does not contact an LEDlight source. A separation distance of the first protruding portion 151and the side surface of the bottom cover 150 is not limited, and may beany distance in which the protruding portion 151 does not contact theLED light source. The second protruding portion 152 may be adjacentlydisposed at one side surface of the bottom cover 150 and may bepositioned at one side edge of the support 123 of the LED assembly 120.

FIG. 3 is a cross-sectional view illustrating an LED assembly and abottom cover in a liquid crystal display according to an embodiment,FIG. 4 is a cross-sectional view illustrating an LED assembly coupled toa bottom cover, FIGS. 5 and 6 are perspective views illustrating an LEDassembly coupled to a bottom cover, and FIG. 7 is anothercross-sectional view illustrating an LED assembly coupled to a bottomcover.

Referring to FIG. 3, the LED assembly 120 may include a plurality of LEDlight sources 121 separated by a predetermined gap, a substrate 122 onwhich the plurality of LED light sources 121 may be mounted, and asupport 123 on which the substrate 122 may be mounted. The LED lightsource 121 may produce white light. The LED light source 121 may be atop view type for emitting light to the top of the LED light source 121opposite to the light guiding plate, or a side view type for emittinglight to a side surface of the LED light source 121, but is not limitedthereto.

Although not shown in the drawings, the substrate 122 may have aplurality of wiring patterns connected to the LED light source 121 toapply an operation current to the LED light source 121. The support 123may couple and support the substrate 122, including the LED light source121 mounted thereon, to the bottom cover 150. The support 123 of the LEDassembly 120 may have an “L” shape cross-section, including a verticalside surface 126 on the vertical portion and a top surface 127 on thehorizontal portion. The LED assembly 120 may also comprise at least onefirst hole 124 and second hole 125 in the support 123 that may couple tothe first protruding portion 151 and the second protruding portion 152of the bottom cover 150. Here, the first hole 124 may be coupled to thefirst protruding portion 151 of the bottom cover 150, and the secondhole 125 may be coupled to the second protruding portion 152 of thebottom cover 150. Moreover, the side cover 155 may be coupled to thebottom cover 150.

Referring to FIGS. 4 to 6, the LED assembly 120 may be coupled to thebottom cover 150. The first protruding portion 151 of the bottom cover150 may be coupled to the first hole 124 provided in the support 123 ofthe LED assembly 120, and the second protruding portion 152 of thebottom cover 150 may be coupled to the second hole 125 of the support123. Moreover, the side cover 155 may be coupled to the bottom cover150.

Here, the first hole 124 provided in the support 123 of the LED assembly120 may be positioned to correspond to the first protruding portion 151of the bottom cover 150. For example, the first hole 124 may be disposedadjacent to one side surface of the support 123 corresponding to thefirst protruding portion 151 of the bottom cover 150, and laterallypositioned at a central part of the one side surface. Further, thesecond hole 125 may be provided on the support 123 of the LED assembly120 to correspond to the second protruding portion 152 of the bottomcover 150. For example, the second hole 125 may be positioned adjacentto an edge of the other side surface of the support 123 that is furtheraway from the LED assembly 120, for example, adjacent to the edge of thehorizontal portion of the support 123.

Still referring to FIGS. 4-6, the first protruding portion 151 of thebottom cover 150 may protrude upward through the first hole 124 of thesupport 123. For example, the first protruding portion 151 may have aheight sufficient to support the reflector 128 and the light guidingplate 131. Further, the second protruding portion 152 of the bottomcover 150 may be positioned not to protrude through the top surface ofthe support 123 when inserted into the second hole 125 of the support123. For example, in order to prevent contact with the reflector 128that is to be coupled, an upper side surface, or top surface, of thesecond protruding portion 152 may be positioned lower than the topsurface of the support 123. Alternatively, the upper side surface of thesecond protruding portion 152 may be positioned on the same line as, orco-planar with, the top surface of the horizontal portion of support123.

Referring to FIG. 7, the LED light sources 121 arranged on the substrate122 may be separated by a predetermined gap. Here, the LED light source121 may be positioned outside an area corresponding to the firstprotruding portion 151 of the bottom cover 150. For example, lightemitted from the LED light source 121 may be disturbed or obstructed dueto the first protruding portion 151 positioned between the LED lightsource 121 and the light guiding plate. When the LED light source 121 ispositioned at an area corresponding to the first protruding portion 151,light emitted from the LED light source 121 may be reflected andscattered by the first protruding portion 151. Thus, one surface of thefirst protruding portion 151 facing the LED light source 121 may have ahigh luminance, and an opposite surface thereof may have a relativelylow luminance resulting in lower light source efficiency.

In order to reduce such a difference in luminance, the LED light source121 may be disposed away from an area corresponding to the firstprotruding portion 151. For example, the first protruding portion 151may be positioned between the LED light sources 121. Here, a gap d1between the LED light sources 121 corresponding to the first protrudingportion 151 may be equal to or larger than a width d2 of the firstprotruding portion 151. Therefore, light emitted from the LED lightsource 121 is not reflected or blocked by the first protruding portion151 and may advance to the light guide plate, thereby reducing aluminance difference caused by the first protruding portion 151.

FIG. 8 is a top plan view and a cross-sectional view illustrating areflector according to an embodiment, and FIGS. 9 and 10 are across-sectional view and a perspective view illustrating a reflectorcoupled to a bottom cover. Referring to FIG. 8, a reflector 128according to this embodiment may include at least one second concaveportion 129 at one side surface thereof. The second concave portion 129of the reflector 128 may have a shape concavely depressed or recessedfrom one side surface of the reflector 128 towards a central part of thereflector 128. The second concave portion 129 of the reflector 128 mayhave a size in which the reflector 128 does not move once it is coupledto the first protruding portion 151 of the bottom cover 150. Forexample, a size of the second concave portion 129 may be equal to orlarger than a width of the first protruding portion 151, but sufficientto fix the reflector 128 to the bottom cover 150.

Referring to FIGS. 9 and 10, the second concave portion 129 may becoupled to the first protruding portion 151 of the bottom cover 150 tocouple and support the reflector 128 to the bottom cover 150. The firstprotruding portion 151 may protrude upward, through the second concaveportion 129 of the reflector 128, and the second protruding portion 152of the bottom cover 150 may be positioned to prevent contact with thereflector 128. Further, referring to FIG. 9, the reflector 128 may bepositioned on the support 123 at a lower part of the LED light source121 to prevent blocking light emitted from the LED light source 121.

FIG. 11 is a top plan view and a cross-sectional view illustrating alight guiding plate according to an embodiment, and FIGS. 12 to 14 arecross-sectional views and a perspective view illustrating a lightguiding plate coupled to a bottom cover. Referring to FIG. 11, a lightguiding plate 131 according to this embodiment may include at least onefirst concave portion 135 at a side surface thereof. The first concaveportion 135 of the light guiding plate 131 may have a shape concavelydepressed or recessed from one side surface of the light guiding plate131 to a central part of the light guiding plate 131. The first concaveportion 135 of the light guiding plate 131 may have a size in which thelight guiding plate 131 does not move once it is coupled to the firstprotruding portion 151 of the bottom cover 150. For example, a size ofthe first concave portion 135 may be equal to or larger than that of thefirst protruding portion 151.

Referring to FIGS. 12 to 14, the light guiding plate 131 may comprise alight emitting plane 133 for emitting light applied from the LED lightsource 121, and the first concave portion 135 of the light guiding plate131 may be coupled to the first protruding portion 151 of the bottomcover 150 to couple and support the light guiding plate 131 to thebottom cover 150.

For example, as shown in FIG. 12, the first protruding portion 151 maybe disposed to not protrude beyond the light emitting plane 133 of thelight guiding plate 131 when placed in the first concave portion 135 ofthe light guiding plate 131. Further, an upper side surface, or topsurface, of the first protruding portion 151 may be positioned at thesame height as the light emitting plane 133 of the light guiding plate131, or may also be positioned lower than the light emitting plane 133of the light guiding plate 131. Here, the upper side surface of thefirst protruding portion 131 may be positioned equal to or higher than ahorizon line HL at a ½ point of a height of the light guiding plate 131.Therefore, the first protruding portion 151 may support the lightguiding plate 131 so that the light guiding plate 131 is not moved orseparated, thereby providing reliable coupling between the light guidingplate 131 and the first protruding portion 151.

In another example, as shown in FIG. 13, the first protruding portion151 may be coupled to the light guiding plate 131 such that it protrudesupward, beyond the light emitting plane 133 of the light guiding plate131, but below an upper surface BS of the side cover 155. This mayprevent an optical sheet that may be positioned above the light guidingplate 131, from coming in contact with the light guiding plate 131,thereby preventing damage to the optical sheet. For example, a diffusionsheet, positioned at a lowest portion of an optical sheet, may beprotected from the first protruding portion 151. Here, the firstprotruding portion 151 may protrude with a minimum margin upward, beyondthe light emitting plane 133 of the light guiding plate 131. Further,the light guiding plate 131 may be positioned on the reflector 128, andmay be positioned such that a side surface of the light guiding plate131 may face and cover a light emitting surface of the LED light source121 in order to receive all light emitted from the LED light source 121.

FIG. 15 is a top plan view illustrating an area I of FIG. 14. Referringto FIG. 15, the first concave portion 135 of the light guiding plate 131may be coupled to the first protruding portion 151 positioned on thebottom cover 150. At one side edge of the bottom cover 150, thesubstrate 122, on which a plurality of LED light sources 121 aredisposed, may be coupled to the support 123. The plurality of LED lightsources 121 may comprise a first LED light source 121a, a second LEDlight source 121b, and a third LED light source 121c. Here, a first gapP1 between the first LED light source 121a and the second LED lightsource 121b may be smaller than a second gap P2 between the second LEDlight source 121b and the third LED light source 121c.

For example, the second gap P2 between the second LED light source 121band the third LED light source 121c corresponding to the firstprotruding portion 151 may be larger than the first gap P1 between thefirst LED light source 121a and the second LED light source 121b. Thismay reduce light emitted from the LED light source 121 from beingdisturbed by the first protruding portion 151 positioned between the LEDlight source 121 and the light guiding plate 131.

When the LED light source 121 is positioned at an area corresponding tothe first protruding portion 151, light emitted from the LED lightsource 121 may be reflected and scattered by the first protrudingportion 151, and thus, at a first surface of the first protrudingportion 151 facing the LED light source 121, light may have a higherluminance than at an opposite surface thereof where light may have arelatively low luminance. Therefore, in order to prevent such adifference in luminance, the first gap P1 between the first LED lightsource 121a and the second LED light source 121b may be formed to besmaller than the second gap P2 between the second LED light source 121band the third LED light source 121c. Further, the second gap P2, thefirst protruding portion 151, and the first concave portion 135 may bepositioned to correspond to each other, for example, centered along thesame line.

FIG. 16 illustrates a first and second concave portions of the reflector128 or the light guiding plate 131. FIGS. 16(a), 16(c), and 16(e) arepartial perspective views of the first and second concave portions.FIGS. 16(b), 16(d), and 16(f) are cross-sectional views corresponding toFIGS. 16(a), 16(c), and 16(e), respectively.

In the foregoing description, simply for ease of explanation, a shape ofthe first concave portion 135 of the light guiding plate 131 has beendescribed as a shape concavely depressed, or recessed, at a central partof one side surface of the light guiding plate 131, and a shape of thesecond concave portion 129 of the reflector 128 has been described as ashape concavely depressed, or recessed, at a central part of one sidesurface of the reflector 128. However, the first concave portion 135 andthe second concave portion 129 may be formed in other shapes or forms,for example, as a hole or slot. Referring to FIG. 16(a) and FIG. 16(b),which is a cross-sectional view of FIG. 16(a), the first concave portion135 of the light guiding plate 131 may be formed in a hole shape. Thatis, a hole may be formed in a central part of one side surface of thelight guiding plate 131. Likewise, the second concave portion of thereflector 128 may be formed in the same shape as that of the firstconcave portion 135 of the light guiding plate 131.

Further, referring to FIG. 16(c) and FIG. 16(d), which is across-sectional view of FIG. 16(c), the first concave portion 135 of thelight guiding plate 131 may have a shape concavely depressed from alower part of the light guiding plate 131 to a depth that may be onehalf the thickness of the light guiding plate 131. Referring to FIG.16(e) and FIG. 16(f), which is a cross-sectional view of FIG. 16(e), thefirst concave portion 135 of the light guiding plate 131 may have ashape in which a lower side surface of the light guiding plate 131 maybe concavely depressed to a depth that may be one half the thickness ofthe light guiding plate 131. In this embodiment, various shapes of thefirst and second concave portions are shown, but the first and secondconcave portions may have any other appropriate shape in which the lightguiding plate 131 or the reflector 128 may be fixed to the firstprotruding portion 135.

According to an embodiment, when the LED assembly 120 is positioned atone side of the bottom cover 150, the LED assembly 120 may include afirst protruding portion 151 and a second protruding portion 152 at oneside edge of the bottom cover 150. The first protruding portion 151 andthe second protruding portion 152 may couple and support the LEDassembly 120, the reflector 128, and the light guiding plate 131. Thus,reliability of the LED assembly 120, the reflector 128, and the lightguiding plate 131 coupled to the bottom cover 150 may be improved.

FIGS. 17 to 23 are cross-sectional views and perspective viewsillustrating a backlight unit according to another embodiment. Referringto FIG. 17, the bottom cover 250 may comprise a first protruding portion251 positioned adjacent both a first side edge and an opposite sideedge, and a second protruding portion 252 positioned adjacent one sideedge at which the LED assembly 220 is positioned. Moreover, the sidecover 255 may be coupled to the bottom cover 250.

The LED assembly 220 may be coupled to the bottom cover 250 at frontsurface of the bottom cover 250, and may comprise an LED light source221, and a substrate 222 to which the LED light source 221 may bemounted, and a support 223 to which the substrate 222 may be mounted. Afirst hole 224 and a second hole 225 may be positioned on the support223 corresponding to the first protruding portion 251 and the secondprotruding portion 252 of the bottom cover 250, respectively, to becoupled thereto.

Second concave portions 229 of the reflector 228 may be positionedadjacent each side edge of the reflector 228 corresponding to each ofthe first protruding portions 251 adjacent each side edge of the bottomcover 250, respectively, to be coupled thereto. First concave portions235 of the light guiding plate 231 may be positioned adjacent each sideedge of the light guide plate 231 corresponding to each of the firstprotruding portions 251 of the bottom cover 250, respectively, to becoupled thereto.

In an embodiment, the light guide plate 231 may include a firstprotruding portion 251 positioned at opposite side edges of the bottomcover 250 and a second protruding portion 252 positioned at one sideedge at which the LED assembly 220 is positioned. The first protrudingportions 251 and the second protruding portions 252 may couple andsupport the LED assembly 220, and may also couple and support thereflector 228 and the light guiding plate 231 at both sides. Thus,reliability of the LED assembly 220, the light guiding plate 231, andthe reflector 228 coupled to the bottom cover 250 may be improved.

Referring to FIG. 18, a bottom cover 350 may include first protrudingportions 351 positioned adjacent to each of four side edges of thebottom cover 350, and a second protruding portion 352 positionedadjacent to one side edge at which the LED assembly 320 is positioned.The LED assembly 320 may be coupled to the bottom cover 350 at frontsurface of the bottom cover 350, and may include an LED light source321, a substrate 322 on which the LED light sources 321 may be mounted,and a support 323 on which the substrate 322 may be mounted. A firsthole 324 and a second hole 325 may be positioned at the support 323corresponding to a first protruding portion 351 and a second protrudingportion 352 of the bottom cover 350, respectively, to be coupledthereto. Moreover, the side cover 355 may be coupled to the bottom cover350.

Second concave portions 329 may be positioned at each of four side edgesof a reflector 328 corresponding to each of the four first protrudingportions 351 of the bottom cover 350, respectively. The reflector 328may be mounted on the LED assembly 320 and the bottom cover 350 usingthe first protruding portions 351. First concave portions 335 may bepositioned at each of the four side edges of the light guiding plate 331corresponding to each of the four second concave portions 329 of thereflector 328. The light guide plate 331 may be positioned on thereflector 328 to be coupled to the bottom cover 350 using the firstprotruding portions 351 of the bottom cover 350.

In an embodiment, the light guide plate 331 may include first protrudingportions 351 positioned at each of the four side edges of the bottomcover, and a second protruding portion 352 positioned at one side edgeat which the LED assembly 320 is positioned. The first protrudingportion 351 and the second protruding portion 352 may couple and supportthe LED assembly 320, and may further couple and support the reflector328 and the light guiding plate 331 at the four sides. Thus, reliabilityof the LED assembly 320, the light guiding plate 331, and the reflector328 coupled to the bottom cover 350 may be improved.

Referring to FIG. 19, in another embodiment, a bottom cover 450 mayinclude a first protruding portion 451 and a second protruding portion452 positioned adjacent to a first side edge and a second side edge thatis opposite the first side edge. The LED assembly 420 may be coupled tothe bottom cover 450 and positioned adjacent to each of a first andsecond side edges of the bottom cover 450, and may include an LED lightsource 421, a substrate 422 on which the LED light source may bemounted, and a support 423 on which the substrate 422 may be mounted. Afirst hole 424 and a second hole 425 may be positioned at the support423 corresponding to the first protruding portion 451 and the secondprotruding portion 452 of the bottom cover 450, respectively, to becoupled thereto. Moreover, the side cover 455 may be coupled to thebottom cover 450.

Second concave portions 429 positioned adjacent to each of a first andsecond side edges of a reflector 428 may be formed in the reflector 428to correspond to the first protruding portions 451. The reflector 428may be coupled to the first protruding portions 451 of the bottom cover450 to be positioned on the supports 423 and the bottom cover 450. Firstconcave portions 435 positioned adjacent to each of a first and secondside edges of the light guiding plate 431 may be formed in the lightguiding plate 431 to correspond to the first protruding portions 451.The light guiding plate 431 may be coupled to the first protrudingportions 451 of the bottom cover 450 to be positioned on the reflector428.

As described above, when the LED assembly 420 is positioned at each ofthe first and second side edges of the bottom cover 450, the LEDassembly 420 may include a first protruding portion 451 and a secondprotruding portion 452 positioned near each of the first and second sideedges of the bottom cover 450. The first protruding portion 451 and thesecond protruding portion 452 may couple and support the LED assembly420, the reflector 428, and the light guiding plate 431 at both sidescorresponding to the protruding portions, thereby improving reliabilityof the LED assembly 420, the reflector 428, and the light guiding plate431 coupled to the bottom cover 450.

Further, referring to FIG. 20, a bottom cover 550 may comprise a firstprotruding portion 551 and a second protruding portion 552 positioned ateach of four side edges. An LED assembly 520 may be coupled to thebottom cover 550 at each of a first and second side edges of the bottomcover 550, and may comprise an LED light source 521, a substrate 522 onwhich the LED light source 521 may be mounted, and a support 523 onwhich the substrate 522 may be mounted. Further, the side cover 555 maybe coupled to the bottom cover 550.

A first hole 524 and a second hole 525 may be positioned on the support523 to be coupled to the first protruding portion 551 and the secondprotruding portion 552, respectively, of the bottom cover 550. Secondconcave portions 529 may be positioned at each of four side edges of areflector 528, and may be formed to correspond to the first protrudingportions 551 of the bottom cover 550 such that the reflector 528 may bepositioned on the support 523 and the bottom cover 550 by coupling toeach of the first protruding portions 551, respectively, of the bottomcover 550. First concave portions 535 may be positioned at each of fourside edges of a light guiding plate 531, and may be positioned at thelight guiding plate 531 positioned on the reflector 528 to be coupled tothe first protruding portions 551, respectively, of the bottom cover550.

In this embodiment, the LED assembly 520 may be positioned at the firstand second side edges of the bottom cover 550. The bottom cover 550 mayinclude a second protruding portion 552 positioned adjacent to each of afirst and second side edges at which the LED assembly 520 may bepositioned such that the second protruding portion may couple andsupport the LED assembly 520. The bottom cover 550 may further include afirst protruding portion 551 positioned adjacent to each of the fourside edges of the bottom cover 550 to couple and support the reflector528 and the light guiding plate 531 at each of the four sides, therebyimproving reliability of the LED assembly 520, the reflector 528, andthe light guiding plate 531 coupled to the bottom cover 550.

Referring to FIG. 21, in this embodiment, a bottom cover 650 may includea first protruding portion 651 and a second protruding portion 652positioned adjacent to each of the four side edges. The LED assembly 620may be coupled to the bottom cover 650 at each of the four side edges ofthe bottom cover 650, and may include a substrate 622 and a support 623including an LED light source 621 mounted thereon. A first hole 624 anda second hole 625 may be positioned at the support 623 and may becoupled to the first protruding portion 651 and the second protrudingportion 652 of the bottom cover 650, respectively. Moreover, the sidecover 655 may be coupled to the bottom cover 650.

A second concave portion 629 may be positioned at each of the four sideedges of a reflector 628, such that the reflector 628 may be positionedon the support 623 and the bottom cover 650 by coupling to each of thefour first protruding portions 651, respectively, of the bottom cover650. A first concave portion 635 may be positioned at each of four sideedges of a light guiding plate 631 and may be coupled to each of thefour corresponding first protruding portions 651 of the bottom cover650.

In this embodiment, when the LED assembly 620 is positioned at each ofthe four side edges of the bottom cover 650, the LED assembly 620 maycomprise second protruding portions 652 positioned adjacent each of thefour side edges of the bottom cover 650 having the LED assemblypositioned thereon such that the second protruding portions 652 maycouple and support the LED assembly 620. The LED assembly 620 may alsoinclude first protruding portions 651 positioned adjacent each of thefour side edges of the bottom cover 650 such that the first protrudingportions 651 may couple and support the reflector 628 and the lightguiding plate 631 at each of the respective four sides, therebyimproving reliability of the LED assembly 620, the reflector 628, andthe light guiding plate 631 coupled to the bottom cover 650.

In the foregoing embodiments, the first protruding portion of the bottomcover may be positioned near a central part, or a midpoint, of at leastone side of the bottom cover 650. Further, the first concave portion ofthe light guiding plate may be positioned at a central part, or amidpoint, of at least one side of the light guiding plate. The secondconcave portion of the reflector may likewise be positioned at thecentral part, or a midpoint, of at least one side of the reflector.

Referring to FIG. 22, in another embodiment, a bottom cover 750 mayinclude first protruding portions 751 positioned at a first and secondcorner opposite to each other, and second protruding portions 752 may bepositioned near each of the four side edges of the bottom cover 750. TheLED assemblies 720 may be coupled to the bottom cover 750, andpositioned at each of four side edges of the bottom cover 750. Each LEDassembly 720 may include an LED light source 721, a substrate 722, and asupport 723. A first hole 724 and a second hole 725 may be positioned atthe support 723 to be coupled to the first protruding portion 751 andthe second protruding portion 752, respectively, of the bottom cover750. Moreover, the side cover 755 may be coupled to the bottom cover750.

Second concave portions 729 positioned at each of both side edgesopposite to a reflector 728 are formed in the reflector 728 positionedon the support 723 and the bottom cover 750 to be coupled to the firstprotruding portions 751, respectively, of the bottom cover 750. Firstconcave portions 735 may be positioned at each of the first and secondside edges and may be coupled to corresponding first protruding portions751 of the bottom cover 750. In this embodiment, by providing eachconcave portion 735 of the light guiding plate 731 and the reflector 728at opposite corners to correspond to the first protruding portion 751provided at opposite corners of the bottom cover 750, reliability of thereflector 728 and the light guiding plate 731 coupled to the bottomcover 750 may be improved.

Further, as shown in FIG. 23, the bottom cover 750 may comprise firstprotruding portions 751 positioned near each of four corners and secondprotruding portions 752 may be positioned near the four side corners.Second concave portions 729 may be positioned at each of four sidecorners of the reflector 728 that may be positioned on the support 723and the bottom cover 750, and each of the second concave portions 729may be coupled to each corresponding first protruding portions 751 ofthe bottom cover 750. First concave portions 735 may be positioned ateach of four side corners of the light guiding plate 731 that may bepositioned on the reflector 728, and each of the first concave portions735 may be coupled to each corresponding first protruding portions 751of the bottom cover 750. In this embodiment, by providing each concaveportion of the light guiding plate 731 and the reflector 728 at each ofthe four side corners to correspond to the first protruding portion 751provided in each of the four side corners of the bottom cover 750,reliability of the reflector 728 and the light guiding plate 731 coupledto the bottom cover 750 may be improved.

FIGS. 24 to 26 illustrate an LED light source of various shapes whichmay be used. Referring to FIG. 24, an LED light source 800 may comprisean LED body 810, a light emitting element 820 which may be positioned onthe LED body 810, a filling material 830 that may cover the lightemitting element 820, and a lens 840 which may be provided on the LEDbody 810.

The LED body 810 may form a body of the LED light source 800 and may bemade of a conductive material, for example, aluminum or otherappropriate materials, to function as a heat sink. The light emittingelement 820 may be formed of a semiconductor material having an energydifference between valence band electrons and conduction band electrons,and may emit red color light, green color light, or blue color light.

The filling material 830 may cover the light emitting element 820 andmay be made of an epoxy, silicone gel, or other appropriate materials. Aspecific color phosphor may be mixed thereto to vary the color of thelight emitted. For example, the LED light source 800 having a lightemitting element 820 which emits blue color light may be configured toemit white light using various combinations of the light emittingelement 820 and various color phosphors. The light emitting element 820which emits blue color light may be combined with phosphor that mayabsorb some of the blue color light to emit yellow color light. Further,mixing phosphor that absorbs yellow color light may provide a whitelight emitting element for emitting white color light.

A lens 840 which may cover an upper part of the LED body 810 may beformed in a hemispherical shape, as shown in FIG. 24. This may preventlight emitted from the light emitting element 820 from focusing on aspecific portion within the light guiding plate and may improvediffusion characteristics of light emitted from the light emittingelement 820. Further, as shown in FIG. 25, a central portion of the lens840 may be formed in a pointed groove shape and, as shown in FIG. 26, acentral portion of the lens 840 may be formed in a hemispherical grooveshape. However, lens 840 of the LED light source 800 may be formed invarious shapes and are not limited thereto. Further, an LED light source800 may have a structure in which the lens 840 is not used.

FIGS. 27 and 28 are top plan views illustrating a backlight unitaccording to another embodiment. Referring to FIG. 27, a bottom cover950 of this embodiment may include first protruding portions 951positioned at each of an upper part of the left side and a lower part ofthe right side. For example, the first protruding portions 951 may bepositioned to have differing vertical positions on the bottom cover 950.

The first concave portions 935 may be positioned at an upper part of theleft side and a lower part of the right side of the light guiding plate931, and may be coupled to the corresponding first protruding portions951 of the bottom cover 950. For example, the first concave portion 935may be provided at a same position that corresponds to the position ofthe first protruding portion 951.

The LED assembly 920 may be coupled to the bottom cover 950 and may bepositioned at one side edge of the bottom cover 950. The LED assembly920 may include an LED light source 921, and a substrate 922 and asupport 923 in which the LED light source 921 may be mounted. The lens840 described in FIGS. 24 to 26 may be provided in the LED light source921 of the LED assembly 920.

As shown in FIG. 27, when the liquid crystal display is assembled andpositioned to stand or mounted vertically, the side of the bottom cover950 having the LED assembly 920 mounted thereon may be positioned at thebottom of the display. Therefore, when the liquid crystal display isassembled and positioned for use, the first protruding portions 951 andthe first concave portions 935 are coupled to each other to fix thelight guiding plate 931 in place, thereby preventing the light guidingplate 931 from contacting the LED light source 921 positioned below.

Further, referring to FIG. 28, the first protruding portions 951 may bepositioned at the centers of the left side and the right side of thebottom cover 950. A plurality of first protruding portions 951 may alsobe positioned at the lower side of the bottom cover 950. First concaveportions 935 of the light guiding plate 931 may be positioned tocorrespond to the first protruding portions 951 of the bottom cover 950at the centers of the left side and the right side and at the lower sideof the light guiding plate 931. The first concave portions 935 may thenbe coupled to the first protruding portions 951 to fix the light guidingplate 931 to the bottom cover 950. Further, the side cover 955 may becoupled to the bottom cover 950.

The LED assembly 920 may be coupled to the bottom cover 950, and may bepositioned at a lower side edge of the bottom cover 950. For example, asdescribed above, when the liquid crystal display is completely assembledand positioned for use, for example, mounted vertically or placed tostand, the LED assembly 920 may be positioned on a side edge of thebottom cover 950 at the bottom of the liquid crystal display. The LEDassembly 920 may be protected from damage caused by contact with thelight guiding plate 931 by fixing the light guiding plate 931 to thebottom cover 950 using the first protruding portions 951 and the firstconcave portions 935.

Further, as described above, the first protruding portion 951 mayreflect or scatter light emitted from an LED light source 921, creatinga difference in luminance. Therefore, the first protruding portion 951may be positioned in an area at which a gap is formed between the LEDlight sources 921 that is larger than that in other areas. Positioningthe first protruding portion 951 in a gap between LED light sources 921may reduce interference by the first protruding portion 951 and mayprevent a difference in luminance from occurring on the light guidingplate 931.

In a backlight unit according to another embodiment, a third protrudingportion may be provided in an LED unit assembly. FIG. 29 is a top planview illustrating the backlight unit according to this embodiment, FIG.30 is a cross-sectional view illustrating a backlight unit taken alongline J-J′ of FIG. 29, and FIG. 31 is a top plan view illustrating afront surface of the backlight unit.

Referring to FIGS. 29 and 30, an LED assembly 1020 may include aplurality of LED light sources 1021 which may be separated by apredetermined gap, a substrate 1022 on which the plurality of LED lightsources 1021 may be mounted, and a support 1023 on which the substrate1022 may be mounted. The support 1023 of the LED assembly 1020 may beformed in a bar shape that does not protrude at a lower portion towardsthe LED light source 1021 or the light guiding plate 1031. For example,the support 1023 is not shaped in an “L” shape as in other embodimentspreviously disclosed.

The LED assembly 1020 may be provided on a side edge of the bottom cover1050. A first protruding portion 1051 may be provided on the bottomcover 1050, and may couple the LED assembly 1020 to the bottom cover1050. The LED assembly 1020 may include at least one first hole 1024 inthe support 1023 that may be coupled to the first protruding portion1051 of the bottom cover 1050. Here, the first hole 1024 provided on thesupport 1023 of the LED assembly 1020 may be positioned to correspond tothe first protruding portion 1051 of the bottom cover 1050. Moreover,the side cover 1055 may be coupled to the bottom cover 1050.

Further, in the LED assembly 1020, a third protruding portion 1025 maybe provided on the substrate 1022. The third protruding portion 1025 mayprotrude from the substrate 1022 in a direction in which light isemitted from the LED light source 1021, and may be positioned in betweenthe LED light sources 1021. For example, the third protruding portion1025 may protrude horizontally from the side edge of the bottom cover1050 towards the light guide plate 1031.

The light guiding plate 1031 may be provided on the bottom cover 1050.At least one first concave portion 1032 may be formed on one sidesurface of the light guide plate 1031. The first concave portion 1032 ofthe light guiding plate 1031 may be formed in a shape concavelydepressed, or recessed, from the one side surface of the light guidingplate 1031 towards a central part of the light guiding plate 1031. Thefirst concave portion 1032 of the light guiding plate 1031 may be formedto be a size such that the light guiding plate 1031 may be fixedrelative to the LED assembly 1020 when the third protruding portion 1025is coupled to the first concave portion 1032. The third protrudingportion 1025 of the LED assembly 1020 may be coupled to the firstconcave portion 1032 of the light guiding plate 1031 to support thelight guiding plate 1031, and to prevent the light guiding plate 1031from contacting with the LED light source 1021.

Referring to FIG. 31, the LED assembly 1020 may be coupled to the bottomcover 1050 and may be positioned at one side edge of the bottom cover1050. The LED assembly 1020 may include an LED light source 1021, and asubstrate 1022 and a support 1023 on which the LED light source 1021 maybe mounted. A plurality of third protruding portions 1025 may beprovided on the substrate 1022.

A plurality of first concave portions 1032 may be positioned at a lowerside of the light guiding plate 1031 and may be coupled to eachcorresponding first protruding portions 1025 of the LED assembly 1020.The light guiding plate 1031 may be fixed relative to the LED assembly1020 and the bottom cover 1050 when coupled to the first protrudingportion 1025.

When the liquid crystal display is assembled and positioned vertically,the side of the bottom cover 1050 on which the LED assembly 1020 ismounted may be positioned at the bottom of the liquid crystal display.Therefore, when the liquid crystal display is positioned vertically, theLED assembly 1020 may be protected from possible damage caused bycontact with the light guiding plate 1031. The LED assembly 1020 isprotected by fixing the light guiding plate 931 to the bottom cover 950using the first protruding portions 1025 and the first concave portions1032.

Referring now to FIG. 30, a plurality of optical sheets 1060 may bepositioned at an upper part of the side cover 1055. In more detail, theoptical sheet 1060 may be positioned on the side cover 1055, above thelight guiding plate 1031 and the LED assembly 1020. Further, the opticalsheet 1060 may be fixed to the side cover 1055. Although not shown inFIG. 30, a plurality of holes may be formed at outside edges of theoptical sheet 1060, and a plurality of corresponding protruding portionsmay be formed at the upper side of the side cover 1055. The hole of theoptical sheet 1060 may be coupled to the protruding portion of the sidecover 1055 to fix the optical sheet 1060 on the side cover 1055.

FIGS. 32 to 34 are top plan views illustrating a front surface of abacklight unit according to another embodiment. Referring to FIG. 32,the backlight unit shown in FIG. 31 may further include a fourthprotruding portion 1056 that may protrude from a side surface of theside cover 1055. The fourth protruding portion 1056 of the side cover1055 may be shaped to protrude from the side surface of the side cover1055 towards the light guiding plate 1031. The fourth protruding portion1056 may be positioned at the center of a left side surface and a rightside surface of the side cover 1055.

The fourth protruding portion 1056 may be coupled to the first concaveportion 1032 of the light guiding plate 1031 to further support thelight guiding plate 1031 together with the third protruding portion 1025provided in the LED assembly 1020. In the light guiding plate 1031, thefirst concave portion 1032 may be formed at a position corresponding tothe fourth protruding portion 1056 of the side cover 1055, and may bepositioned at the center of the left side and the right side of thelight guiding plate 1031.

Referring to FIGS. 33 and 34, in this embodiment, the fourth protrudingportion 1056 of the side cover 1055 may be formed to couple to the firstconcave portion 1032 of the light guiding plate 1031 without the thirdprotruding portion 1025. For example, as shown in FIG. 33, the fourthprotruding portions 1056 may be provided on each of an upper part of theleft side and a lower part of the right side of the side cover 1055. Thefirst concave portions 1032 may be positioned at an upper part of theleft side and an upper part of the right side of the light guiding plate1031 to correspond to a position of the fourth protruding portion 1056.Therefore, the fourth protruding portion 1056 of the side cover 1055 maybe coupled to the first concave portion 1032 of the light guiding plate1031.

Further, as shown in FIG. 34, the fourth protruding portions 1056 may beprovided at the center of the left side and the right side of the sidecover 1055. The first concave portions 1032 may be positioned at thecenter of the left side and the right side of the light guiding plate1031 to correspond to a position of the fourth protruding portion 1056.Therefore, the fourth protruding portion 1056 of the side cover 1055 maybe coupled to the first concave portion 1032 of the light guiding plate1031.

As described above, in a backlight unit and a liquid crystal displaycomprising the same, a plurality of protruding portions may be formed ona bottom cover to support and couple an LED assembly and a light guidingplate. Further, by preventing the light guiding plate from contactingwith the LED unit assembly through protruding portions of the bottomcover, reliability of the liquid crystal display may be improved.

A liquid crystal display may be used in various fields, for example, innotebook computers and monitors, and may have an advantage over otherdisplay devices because of its small size, light weight, and low powerconsumption. The liquid crystal display may comprise a liquid crystalpanel and a backlight unit. The backlight unit may provide light to theliquid crystal panel, and the light may transmit the liquid crystalpanel. In this case, the liquid crystal panel may display an image byadjusting a transmittance of light.

The backlight unit may be classified into an edge type and a direct typeaccording to a disposition form of a light source. In the edge typebacklight unit, a light source may be disposed at a side surface of aliquid crystal panel, and a light guiding plate may be disposed at arear surface of the liquid crystal panel to guide light provided fromthe side surface of the liquid crystal panel to a rear surface of theliquid crystal panel. In the direct type backlight unit, a plurality oflight sources may be provided in the rear surface of the liquid crystalpanel, and light emitted from the plurality of light sources may bedirectly provided to the rear surface of the liquid crystal panel.

Various light sources may be used, for example, electro luminescence(EL), a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescentlamp (HCFL), a light emitting diode (LED), or other appropriate lightsources. The LED may have a low power consumption and excellent lightemission efficiency. When the LED light source is applied to the edgetype backlight unit, the LED light source may be mounted on thesubstrate, and may be fixed to a side surface of the light guidingplate. The fixing or mounting structure of light guiding plate maybecome complex and may require a complex method of fixing or mountingthe light source and light guiding plate. A backlight unit and a liquidcrystal display comprising the same as broadly disclosed and embodiedherein may fix or mount a light guiding plate thereon to effectivelyapply light emitted from an LED to the light guiding plate.

A display device is broadly described and embodied herein and mayinclude a display panel having a plurality of electrodes and pixels; andan edge type backlight provided adjacent to the display panel, thebacklight having a plurality of optical sheets adjacent to the displaypanel; a light guide panel having at least one light incident area toreceive light from a first direction and a light emitting area to emitlight received through the light incident area in a second directiontowards the plurality of optical sheets, the first and second directionsbeing different directions; at least one light source, at least oneincident area of the light guide panel being adjacent to at least onelight source to receive light output; a reflector adjacent to the lightguide panel to reflect light towards the second direction; and a bottomcover including a plate, the plate provided adjacent to the reflectorand having a prescribed length in the first direction and a prescribedwidth in a third direction, the plate further including at least onepost having a first prescribed height, and the reflector and the lightguide panel having at least one opening having a second prescribedheight to receive the at least one post.

The display device is disclosed wherein the second prescribed heightbeing greater than the first prescribed height; wherein the platefurther includes at least one peg, the at least one peg having a heightless than the at least one post, the at least one post being positionedcloser to the at least one light source than the at least one peg; andwherein the at least one light source comprises a first LED assemblyhaving a plurality of light emitting diodes provided on a firstsubstrate and arranged in the third direction, the LED assembly furtherincluding a first support plate extending in the first direction andprovided adjacent to the first substrate, the first support plateincluding a first opening and a second opening, which are fitted overthe at least one post and the at least one peg.

The display device is disclosed wherein the at least one light sourcecomprises a first LED assembly having a plurality of first lightemitting diodes provided on a first substrate and arranged in the thirddirection, the first LED assembly further including a first supportplate extending in the first direction and provided adjacent to thefirst substrate, the first support plate including a first opening and asecond opening, the at least one post including a first post and atleast one of a second post, a third post or a fourth post, the firstpost located closest in the first direction to the plurality of firstlight emitting diodes, the at least one peg including a first peg, thefirst and second openings fitted over the first post and the first peg,and the at least one opening of the reflector and the light guide panelincludes a first slot and at least one of a second slot, a third slot ora fourth slot.

The display device is disclosed wherein the at least one light sourcefurther comprises a second LED assembly having a plurality of secondlight emitting diodes provided on a second substrate and arranged in thethird direction, the second LED assembly being provided on a side of theplate opposite from the first LED assembly, the second LED assemblyfurther including a second support plate extending in the firstdirection and provided adjacent to the second substrate, the secondsupport plate including a third opening and a fourth opening, the secondpost located closest in the first direction to the plurality of secondlight emitting diodes, the at least one peg further including a secondpeg, and the third and fourth openings fitted over the second post andthe second peg.

The display device is disclosed wherein the at least one light sourcefurther comprises a third LED assembly having a plurality of third lightemitting diodes provided on a third substrate and arranged in the firstdirection, the third LED assembly being provided on a side of the platebetween the first LED assembly and the second LED assembly, the thirdLED assembly further including a third support plate extending in thethird direction and provided adjacent to the third substrate, the thirdsupport plate including a fifth opening and a sixth opening, the thirdpost located closest in the third direction to the plurality of thirdlight emitting diodes, the at least one peg further including a thirdpeg, and the fifth and sixth openings fitted over the third post and thethird peg; and the at least one light source further comprises a fourthLED assembly having a plurality of fourth light emitting diodes providedon a fourth substrate and arranged in the first direction, the fourthLED assembly being provided on a side of the plate between the first LEDassembly and the second LED assembly and opposite of the third LEDassembly, the fourth LED assembly further including a fourth supportplate extending in the third direction and provided adjacent to thefourth substrate, the fourth support plate including a seventh openingand a eighth opening, the fourth post located closest in the thirddirection to the plurality of fourth light emitting diodes, the at leastone peg further including a fourth peg, and the seventh and eighthopenings fitted over the fourth post and the fourth peg.

The display device is disclosed wherein the first and second slots areprovided at diagonally opposite corners of the light guide panel and thereflector, and the first and second slots fit over the first and secondposts of the plate; wherein the first, second, third and fourth slotsare provided at the corners of the light guide panel and the reflector,and the first, second, third and fourth slots fit over the first,second, third and fourth posts of the plate; wherein the at least onefirst post is provided between two adjacent first light emitting diodesseparated by a first prescribed distance while remaining first lightemitting diodes are separated by a second prescribed distance, the firstprescribed distance being greater than the second prescribed distance;and wherein each of the plurality of first light emitting diodesincludes a lens, and the lens includes both a concave portion and aconvex portion.

A display device is broadly described and embodied herein and mayinclude a display panel having a plurality of electrodes and pixels; anda backlight provided adjacent to the display panel, the backlight havinga plurality of optical sheets adjacent to the display panel; a lightguide panel having at least one light incident area to receive lightfrom a first direction and a light emitting area to emit light receivedthrough the light incident area in a second direction towards theplurality of optical sheets, the first and second directions beingdifferent directions; at least one light source, at least one incidentarea of the light guide panel being adjacent to at least one lightsource to receive light output; a reflector adjacent to the light guidepanel to reflect light towards the second direction; and a bottom coverincluding a plate, the plate provided adjacent to the reflector andhaving a prescribed length in the first direction and a prescribed widthin a third direction, the plate further including at least one postextending in the second direction, the at least one light sourcecomprising a first LED assembly having a plurality of first lightemitting diodes provided on a substrate, which is supported by a firstsupport plate, the first support plate having a first opening to receivethe at least one post, the first LED assembly further comprising atleast one peg extending in the first direction, the light guide panelhaving at least one slot to receive the at least one peg.

The display device is disclosed wherein the at least one peg is providedbetween adjacent first light emitting diodes; wherein the at least onepeg and the at least one slot prevent the at least one light guide panelfrom contacting the plurality of first light emitting diodes; andwherein at least one of the first light emitting diodes includes lensfrom which light is output toward the at least one light incident areaof the light guide panel, and a gap is provided between the lens and theat least one light incident area by the at least one peg and the atleast one slot.

The display device is disclosed wherein the at least one peg is providedbetween two adjacent first light emitting diodes separated by a firstprescribed distance while remaining first light emitting diodes areseparated by a second prescribed distance, the first prescribed distancebeing greater than the second prescribed distance; wherein the at leastone peg has a first prescribed height in the second direction, and theat least one light guide panel has a second prescribed height in thesecond direction, the second prescribed height being greater than thefirst prescribed height; wherein the bottom cover includes a first pegon a first side and a second peg on a second side, the at least one pegprovided between the first and second pegs, and the light guide panelfurther includes first and second slots to receive the first and secondpegs; wherein when the display device is oriented in a verticaldirection such that the second direction is perpendicular to thedirection of gravity, the at least one peg and the first and second pegssupport the weight of the light guide panel; and wherein the at leastone peg comprises a plurality of pegs, and the at least one slotcomprises a plurality of slots to receive the plurality of pegs.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A display device comprising: a display panelhaving a plurality of electrodes and pixels; and an edge type backlightprovided adjacent to the display panel, the backlight having a pluralityof optical sheets adjacent to the display panel; a light guide panelhaving at least one light incident area to receive light from a firstdirection and a light emitting area to emit light received through thelight incident area in a second direction towards the plurality ofoptical sheets, the first and second directions being differentdirections; at least one light source, at least one incident area of thelight guide panel being adjacent to at least one light source to receivelight output; a reflector adjacent to the light guide panel to reflectlight towards the second direction; and a bottom cover including aplate, the plate provided adjacent to the reflector and having aprescribed length in the first direction and a prescribed width in athird direction, the plate further including at least one post having afirst prescribed height, and the reflector and the light guide panelhaving at least one opening having a second prescribed height to receivethe at least one post, wherein the plate further includes at least onepeg, the at least one peg having a height less than the at least onepost, the at least one post being positioned closer to the at least onelight source than the at least on peg, and the at least one post and thepeg being separate from each other.
 2. The display device of claim 1,wherein the second prescribed height being greater than the firstprescribed height.
 3. The display device of claim 1, wherein the atleast one light source comprises a first LED assembly having a pluralityof light emitting diodes provided on a first substrate and arranged inthe third direction, the LED assembly further including a first supportplate extending in the first direction and provided adjacent to thefirst substrate, the first support plate including a first opening and asecond opening, which are fitted over the at least one post and the atleast one peg.
 4. A display device of comprising: a display panel havinga plurality of electrodes and pixels; and an edge type backlightprovided adjacent to the display panel, the backlight having a pluralityof optical sheets adjacent to the display panel; a light guide panelhaving at least one light incident area to receive light from a firstdirection and a light emitting area to emit light received through thelight incident area in a second direction towards the plurality ofoptical sheets, the first and second directions being differentdirections; at least one light source, at least one incident area of thelight guide panel being adjacent to at least one light source to receivelight output; a reflector adjacent to the light guide panel to reflectlight towards the second direction; and a bottom cover including aplate, the plate provided adjacent to the reflector and having aprescribed length in the first direction and a prescribed width in athird direction, the plate further including at least one post having afirst prescribed height and the reflector and the light guide panelhaving at least one opening having a second prescribed height to receivethe at least one post, wherein the at least one light source comprises afirst LED assembly having a plurality of first light emitting diodesprovided on a first substrate and arranged in the third direction, thefirst LED assembly further including a first support plate extending inthe first direction and provided adjacent to the first substrate, thefirst support plate including a first opening and a second opening, theat least one post including a first post and at least one of a secondpost, a third post or a fourth post, the first post located closest inthe first direction to the plurality of first light emitting diodes, theat least one peg including a first peg, the first and second openingsfitted over the first post and the first peg, and the at least oneopening of the reflector and the light guide panel includes a first slotand at least one of a second slot, a third slot or a fourth slot.
 5. Thedisplay device of claim 4, wherein the at least one light source furthercomprises a second LED assembly having a plurality of second lightemitting diodes provided on a second substrate and arranged in the thirddirection, the second LED assembly being provided on a side of the plateopposite from the first LED assembly, the second LED assembly furtherincluding a second support plate extending in the first direction andprovided adjacent to the second substrate, the second support plateincluding a third opening and a fourth opening, the second post locatedclosest in the first direction to the plurality of second light emittingdiodes, the at least one peg further including a second peg, and thethird and fourth openings fitted over the second post and the secondpeg.
 6. The display device of claim 5, wherein the at least one lightsource further comprises a third LED assembly having a plurality ofthird light emitting diodes provided on a third substrate and arrangedin the first direction, the third LED assembly being provided on a sideof the plate between the first LED assembly and the second LED assembly,the third LED assembly further including a third support plate extendingin the third direction and provided adjacent to the third substrate, thethird support plate including a fifth opening and a sixth opening, thethird post located closest in the third direction to the plurality ofthird light emitting diodes, the at least one peg further including athird peg, and the fifth and sixth openings fitted over the third postand the third peg; and the at least one light source further comprises afourth LED assembly having a plurality of fourth light emitting diodesprovided on a fourth substrate and arranged in the first direction, thefourth LED assembly being provided on a side of the plate between thefirst LED assembly and the second LED assembly and opposite of the thirdLED assembly, the fourth LED assembly further including a fourth supportplate extending in the third direction and provided adjacent to thefourth substrate, the fourth support plate including a seventh openingand a eighth opening, the fourth post located closest in the thirddirection to the plurality of fourth light emitting diodes, the at leastone peg further including a fourth peg, and the seventh and eighthopenings fitted over the fourth post and the fourth peg.
 7. The displaydevice of claim 4, wherein the first and second slots are provided atdiagonally opposite corners of the light guide panel and the reflector,and the first and second slots fit over the first and second posts ofthe plate.
 8. The display device of claim 7, wherein the first, second,third and fourth slots are provided at the corners of the light guidepanel and the reflector, and the first, second, third and fourth slotsfit over the first, second, third and fourth posts of the plate.
 9. Thedisplay device of claim 3, wherein the at least one first post isprovided between two adjacent first light emitting diodes separated by afirst prescribed distance while remaining first light emitting diodesare separated by a second prescribed distance, the first prescribeddistance being greater than the second prescribed distance.
 10. Thedisplay device of claim 3, wherein each of the plurality of first lightemitting diodes includes a lens, and the lens includes both a concaveportion and a convex portion.
 11. A display device comprising: a displaypanel having a plurality of electrodes and pixels; and a backlightprovided adjacent to the display panel, the backlight having a pluralityof optical sheets adjacent to the display panel; a light guide panelhaving at least one light incident area to receive light from a firstdirection and a light emitting area to emit light received through thelight incident area in a second direction towards the plurality ofoptical sheets, the first and second directions being differentdirections; at least one light source, at least one incident area of thelight guide panel being adjacent to at least one light source to receivelight output; a reflector adjacent to the light guide panel to reflectlight towards the second direction; and a bottom cover including aplate, the plate provided adjacent to the reflector and having aprescribed length in the first direction and a prescribed width in athird direction, the plate further including at least one post extendingin the second direction, the at least one light source comprising afirst LED assembly having a plurality of first light emitting diodesprovided on a substrate, which is supported by a first support plate,the first support plate having a first opening to receive the at leastone post, the first LED assembly further comprising at least one pegextending in the first direction, the light guide panel having at leastone slot to receive the at least one peg.
 12. The display device ofclaim 11, wherein the at least one peg is provided between adjacentfirst light emitting diodes.
 13. The display device of claim 12, whereinthe at least one peg and the at least one slot prevent the at least onelight guide panel from contacting the plurality of first light emittingdiodes.
 14. The display device of claim 12, wherein at least one of thefirst light emitting diodes includes lens from which light is outputtoward the at least one light incident area of the light guide panel,and a gap is provided between the lens and the at least one lightincident area by the at least one peg and the at least one slot.
 15. Thedisplay device of claim 11, wherein the at least one peg is providedbetween two adjacent first light emitting diodes separated by a firstprescribed distance while remaining first light emitting diodes areseparated by a second prescribed distance, the first prescribed distancebeing greater than the second prescribed distance.
 16. The displaydevice of claim 11, wherein the at least one peg has a first prescribedheight in the second direction, and the at least one light guide panelhas a second prescribed height in the second direction, the secondprescribed height being greater than the first prescribed height. 17.The display device of claim 11, wherein the bottom cover includes afirst peg on a first side and a second peg on a second side, the atleast one peg provided between the first and second pegs, and the lightguide panel further includes first and second slots to receive the firstand second pegs.
 18. The display device of claim 17, wherein when thedisplay device is oriented in a vertical direction such that the seconddirection is perpendicular to the direction of gravity, the at least onepeg and the first and second pegs support the weight of the light guidepanel.
 19. The display device of claim 18, wherein the at least one pegcomprises a plurality of pegs, and the at least one slot comprises aplurality of slots to receive the plurality of pegs.
 20. A backlightunit, comprising: a light guiding plate; a light source assemblyincluding at least one light source facing a side surface of the lightguiding plate; a reflector disposed below the light guiding plate toreflect light towards the light guiding plate; a bottom cover,comprising: a plate disposed below the reflector; a first protrusionprotruding at a predetermined length from an upper surface of the plate,the first protrusion configured to be in close contact with the sidesurface of the light guiding plate; and a second protrusion protrudingat a predetermined length from the upper surface of the plate, thesecond protrusion configured to be coupled to the light source assemblyby being inserted in a portion of the light source assembly, wherein thelength of the first protrusion is configured to be different from thelength of the second protrusion, and wherein the first protrusion andthe second protrusion are positioned on the bottom cover such that afirst distance from the first protrusion to a nearest light source isshorter than a second distance from the second protrusion to a nearestlight source.
 21. The backlight unit of claim 20, wherein the length ofthe first protrusion is greater than the length of the secondprotrusion.
 22. The backlight unit of claim 20, wherein the firstprotrusion is configured to be a predetermined distance away from thesecond protrusion.
 23. The backlight unit of claim 20, wherein the lightguiding plate includes at least one opening or recess defined at apredetermined position of the side surface thereof, and wherein thefirst protrusion is inserted in the at least one opening or recess ofthe light guiding plate, thereby supporting the light guiding plate. 24.The backlight unit of claim 20, wherein the reflector includes at leastone opening or recess defined at a predetermined position of a sidesurface thereof, and wherein the first protrusion inserted in the atleast one opening or recess of the reflector, thereby supporting thereflector.
 25. The backlight unit of claim 20, further comprising aplurality of optical sheets placed above the light guiding plate. 26.The backlight unit of claim 20, wherein the light source assemblycomprises: a substrate on which the at least one light source ismounted; and a support on which the substrate is mounted, the supportincluding: a vertical part on which the substrate is mounted; and ahorizontal part perpendicularly bent at a lower end of the vertical partto be placed on the plate, wherein the at least one light sourceincludes an LED.
 27. The backlight unit of claim 26, wherein thereflector is placed on the horizontal part of the support.
 28. Thebacklight unit of claim 27, wherein the second protrusion is configuredto pass through the horizontal part of the support, wherein the lengthof the second protrusion is configured to be identical to or less than athickness of the horizontal part of the support.
 29. The backlight unitof claim 27, wherein the first protrusion is configured to pass throughthe horizontal part of the support.
 30. The backlight unit of claim 20,wherein the second protrusion is disposed below the light guiding plateand the reflector.
 31. The backlight unit of claim 20, wherein when thereflector and the light guiding plate are assembled, a height of anupper end of the first protrusion is identical to or less than a heightof an upper surface of the light guiding plate.
 32. The backlight unitof claim 20, wherein the light source assembly includes: a first lightsource; and a second light source adjacent to the first light source,wherein the first protrusion is positioned between the first and secondlight sources.
 33. The backlight unit of claim 32, wherein the lightsource assembly further includes a third light source adjacent to thesecond light source, wherein a gap between the first and second lightsources is greater than a gap between the second and third lightsources.
 34. The backlight unit of claim 33, wherein the light sourceassembly further includes a fourth light source adjacent to the firstlight source, wherein the gap between the second and third light sourcesis the same as a gap between the first and fourth light source.
 35. Adisplay device, including: a display panel; a backlight unit disposedbelow the display panel, the backlight unit including: a plurality ofoptical sheets disposed below the display panel; a light guiding platedisposed below the plurality of optical sheets; a light source assemblyincluding at least one light source facing a side surface of the lightguiding plate; a reflector disposed below the light guiding plate toreflect light towards the light guiding plate; a bottom cover,comprising: a plate disposed below the reflector; a first protrusionprotruding at a predetermined length from an upper surface of the plate,the first protrusion configured to be in close contact with the sidesurface of the light guiding plate; and a second protrusion protrudingat a predetermined length from the upper surface of the plate, thesecond protrusion configured to be coupled to the light source assemblyby being inserted in a portion of the light source assembly, wherein thelength of the first protrusion is configured to be different from thelength of the second protrusion, wherein the first protrusion and thesecond protrusion are positioned on the bottom cover such that a firstdistance from the first protrusion to the nearest light source isshorter than a second distance from the second protrusion to the nearestlight source.